1. Field of the Invention
The present invention relates to a torque detection device, and in particular to a detection device that finds applications in the operation of torque devices and has coupling ends for selectively coupling with various torque devices and tool pieces in opposite directions for performing detection, transmission, displaying, alarming, and storage of an actual value of torque applied thereto.
2. The Related Arts
A hand tool, electrical tool or pneumatic tool, such as a wrench socket or a spanner, is widely used in assembling and maintenance operations of mechanical engineering for tightening or loosening threaded fasteners, such as nuts and bolts, attached to a machine or a mechanical part. However, for high precision machinery, the nuts or bolts must be tightened or loosened by following predetermined operation processes with preset levels of torques. Improper operation of a hand tool, an electrical tool, or a pneumatic tool to apply a torque may inadvertently cause damage or breaking of a threaded fastener or a threaded hole, and may thus lead to undesired damage to the functionality and operation precision of the machine. The conventional hand tools, electric tools, or pneumatic tools are not capable of detecting and displaying the value of a torque applied in an operation, whereby a user cannot get aware of the level of torque applied and must thus depend on his or her experience and discretion to operate the hand tool or electric or pneumatic tool. This may lead to improper application of torque due to human errors. On the other hand, if each hand tool, electric tool, or pneumatic tool is individually provided with a specific torque detector in order to provide torque detectable hand tool, electric tool, or pneumatic tool, then the costs for design and manufacture of the tools must be greatly increased, and this arrangement may not be feasible for all applications where hand tools, electrical tools, and pneumatic tools are used to apply a torque to a workpiece.
Other prior art references in this field are also known. For example, Taiwan Patent No. I300027 discloses a torque wrench having a driving head that is provided with a torque display device, and Taiwan Patent No. I307305 discloses a digital alarm device for torque wrenches. Both Taiwan patents illustrate conventional solutions that mount torque detection/displaying or alarming devices to torque wrenches for the purposes of realizing detection of torque. However, in such known solutions, mounting the torque detection and displaying device to the torque wrench is a difficult operation and this makes the manufacturing of the torque wrench very complicated. Further, both patents provide a solution of torque detection that is only applicable to specific torque wrenches and is not suitable for all kinds of hand tools, electrical tools, and pneumatic tools.
Other prior art references include Taiwan Utility Model No. M367059, which discloses an extender device with digital display for a torque tool. The extender device of this Taiwan Utility Model comprises an extension bar having two ends forming first and second coupling sections respectively. The first coupling section is made in the form of a column-like projection for coupling with for example a wrench socket, while the second coupling section is made in the form of a recessed cavity for coupling with a torque tool, such as a torque wrench, whereby the torque tool may apply a torque to the socket through the extension bar. The extension bar has a connecting section bridging between the coupling ends and forming a machined flat surface to which a sensor is mounted to detect the torque transmitted through the extension bar. The sensor is electrically connected, in a wired manner, to a display unit that shows the detected value of torque.
The structure of the Taiwan Utility Model requires the sensor 20 to be securely attached to the flat face formed on the connecting section of the extension bar in order to properly detect the value of torque. This makes the manufacturing of the extension bar very complicated and also imposes unnecessary constraint to the positioning and mounting of the sensor to the extension bar. Further, it often cause error of detection by using the extension bar that is machined to form the flat face in the connecting section, leading poor performance of torque detection and displaying of the extender device.
In addition, the extension bar illustrated in this Taiwan Utility Model is provided with first and second coupling sections that are of fixed sizes and thus only fit for a torque tool and a socket of given sizes. If tools and sockets of different sizes are desired, then the extension bar must be replaced by different ones. However, due to the sensor that is mounted to the flat face of the connecting section is in wired connection with a circuit board of the display unit, simply replacing the extension bar is not feasible at all. Consequently, extender devices of numerous sizes, which contain extension bars having differently-sized coupling sections, must be prepared in order to carry out operation of tightening and loosening on fasteners of different sizes. This is not economically feasible in view of the costs required.
The first and second coupling sections of the extension bar of the Taiwan Utility Model and the display unit connected thereto allow for only a specific direction use. In other words, a user must distinguish the first coupling section from the second coupling section before he or she can use a torque tool and an associated socket, which can only and respectively connected to the second and first coupling sections and cannot switch with each other. Besides such inconvenience occurring in using the extender device, when the torque tool is set at a given direction, such as the socket being pointed downward, the digits displayed on a display panel of the display unit is visually observable and identifiable, but when the torque tool is set at an opposite direction, such as the socket being pointed upward, the orientation of the digits on the display panel is reversed, making it difficult for a user to read the digits.
In addition, the extender device of the Taiwan Utility Model allows for separation of the extension bar and the display unit. However, when they are spaced from each other, electrical wires are needed to connect the sensor mounted on the extension bar and the circuit board of the display unit in order to transmit the value of torque detected by the sensor to the circuit board of the display unit. Besides the problem mentioned above that the extension bar is only fit for a torque tool of a specific size and an associated socket, this arrangement of wired connection imposes a significant constraint to the operation range of rotation of the tool and the socket, because the wires have only a limited length, which limits the operation space of the tool and the socket connected to the extension bar. Further, the rotation angle of the tool and the socket is also limited and once the rotation is done for an excessive angle, the wires may entangle the extension bar or the wires may detach from the circuit board or the sensor.